A novel class of Candida glabrata cell wall proteins with β-helix fold mediates adhesion in clinical isolates

Candida glabrata is an opportunistic pathogenic yeast frequently causing infections in humans. Though it lacks typical virulence factors such as hyphal development, C. glabrata contains a remarkably large and diverse set of putative wall adhesins that is crucial for its success as pathogen. Here, we present an analysis of putative adhesins from the homology clusters V and VI. First, sequence similarity network analysis revealed relationships between cluster V and VI adhesins and S. cerevisiae haze protective factors (Hpf). Crystal structures of A-domains from cluster VI adhesins Awp1 and Awp3b reveal a parallel right-handed β-helix domain that is linked to a C-terminal β-sandwich. Structure solution of the A-region of Awp3b via single wavelength anomalous diffraction phasing revealed the largest known lanthanide cluster with 21 Gd3+ ions. Awp1-A and Awp3b-A show structural similarity to pectate lyases but binding to neither carbohydrates nor Ca2+ was observed. Phenotypic analysis of awp1Δ, awp3Δ, and awp1,3Δ double mutants did also not confirm their role as adhesins. In contrast, deletion mutants of the cluster V adhesin Awp2 in the hyperadhesive clinical isolate PEU382 demonstrated its importance for adhesion to polystyrene or glass, biofilm formation, cell aggregation and other cell surface-related phenotypes. Together with cluster III and VII adhesins our study shows that C. glabrata CBS138 can rely on a set of 42 Awp1-related adhesins with β-helix/α-crystallin domain architecture for modifying the surface characteristics of its cell wall.

Copper Acts Synergistically with Fluconazole in Candida glabrata by Compromising Drug Efflux, Sterol Metabolism, and Zinc Homeostasis

The synergistic combinations of drugs are promising strategies to boost the effectiveness of current antifungals and thus prevent the emergence of resistance. In this work, we show that copper and the antifungal fluconazole act synergistically against Candida glabrata, an opportunistic pathogenic yeast intrinsically tolerant to fluconazole. Analyses of the transcriptomic profile of C. glabrata after the combination of copper and fluconazole showed that the expression of the multidrug transporter gene CDR1 was decreased, suggesting that fluconazole efflux could be affected. In agreement, we observed that copper inhibits the transactivation of Pdr1, the transcription regulator of multidrug transporters, and leads to the intracellular accumulation of fluconazole. Copper also decreases the transcriptional induction of ergosterol biosynthesis (ERG) genes by fluconazole, which culminates in the accumulation of toxic sterols. Co-treatment of cells with copper and fluconazole should affect the function of proteins located in the plasma membrane, as several ultrastructural alterations, including irregular cell wall and plasma membrane and loss of cell wall integrity, were observed. Finally, we show that the combination of copper and fluconazole downregulates the expression of the gene encoding the zinc-responsive transcription regulator Zap1, which possibly, together with the membrane transporters malfunction, generates zinc depletion. Supplementation with zinc reverts the toxic effect of combining copper with fluconazole, underscoring the importance of this metal in the observed synergistic effect. Overall, this work, while unveiling the molecular basis that supports the use of copper to enhance the effectiveness of fluconazole, paves the way for the development of new metal-based antifungal strategies.

Influence of grain physical characteristics on functional value of poultry feed

The purpose of this investigation was to analyze the scientific literature concerning the influence of grain physical characteristics on functional value of poultry feed. The review considers the role of grain feed particle size and its shape in ensuring optimal development and functioning of digestive tract and increasing productivity of birds. The results showed that compared to the feeding with smaller particles, the use of coarse feed increased stomach weight in broilers, enhanced enzymatic degradation of feed in digestive tract and improved nutrient bioavailability. The study found that increase in the level of coarse corn in the diet increased the number of Lactobacillus spp. and Bifidobacteria spp. beneficial bacteria in digestive tract. Meanwhile, number of opportunistic pathogenic microorganisms decreased. In birds which were given granular feed we found insufficient development of stomach, mainly due to the lack of mechanical stimulation. We assume that in order to improve stomach function and health of birds, it is necessary to apply a source of dietary fiber to their diet. The results of studies suggest that adding 2-3% of insoluble source of fiber to the routine diets of young chickens based on high-protein soy flour and corn can improve their digestive tract development and growth characteristics.

Characteristics of a Bacteriophage, vB_Kox_ZX8, Isolated From Clinical Klebsiella oxytoca and Its Therapeutic Effect on Mice Bacteremia

Klebsiella oxytoca is an important nosocomial and community-acquired opportunistic pathogenic Klebsiella and has become the second most prevalent strain in the clinic after K. pneumoniae. However, there have been few reports of bacteriophages used for treating K. oxytoca. In this study, a novel bacteriophage, vB_Kox_ZX8, which specifically infects K. oxytoca AD3, was isolated for the first time from human fecal samples. The biological characteristics of vB_Kox_ZX8 showed an incubation period of 10 min, a burst size of 74 PFU/cell, and a stable pH range of 3–11. Genomic bioinformatics studies of vB_Kox_ZX8 showed that it belongs to the genus Przondovirus, subfamily Studiervirinae, family Autographiviridae. The genome of vB_Kox_ZX8 is 39,398 bp in length and contains 46 putative open reading frames encoding functional proteins, such as DNA degradation, packaging, structural, lysin-holin, and hypothetical proteins. We further investigated the efficacy of vB_Kox_ZX8 phage in the treatment of mice with bacteremia caused by K. oxytoca infection. The results showed that vB_Kox_ZX8 (5 × 109 PFU/mouse) injected intraperitoneally alone was metabolized rapidly in BALB/c mice, and no significant side effects were observed in the control and treatment groups. Importantly, intraperitoneal injection with a single dose of phage vB_Kox_ZX8 (5 × 107 PFU/mouse) for 1 h post-infection saved 100% of BALB/c mice from bacteremia induced by intraperitoneal challenge with a minimum lethal dose of K. oxytoca AD3. However, all negative control mice injected with PBS alone died. Owing to its good safety, narrow host infectivity, high lysis efficiency in vitro, and good in vivo therapeutic effect, phage vB_Kox_ZX8 has the potential to be an excellent antibacterial agent for clinical K. oxytoca-caused infections.

Disseminated Nocardia farcinica involves the spinal cord: a case report and review of the literature

Background Nocardia is a relatively rare opportunistic pathogenic bacteria group, commonly seen in patients with immunocompromised or defective immune system. It can affect multiple organs of the body and cause disseminated infection, among which most occurs in the lung, secondly in the nervous system, soft tissues, rare in the spinal cord and pituitary. No case has been reported involving lung, spinal cord, skin and pituitary gland at the same time. Case presentation We report a 55-year-old female with Nocardia infection involving the lung, skin, spinal cord, and pituitary gland. The patient underwent a full set of imaging examinations and showed typical imaging findings. Chest computed tomography (CT) showed multiple nodules with cavities in the lungs. The magnetic resonance imaging (MRI) of the vertebral body showed abnormal signal of the entire spinal cord with cavity formation and ring enhancement. The subcutaneous nodules of the abdomen were punctured under ultrasound. Through the etiological tissue culture of subcutaneous nodules and the second generation sequencing of cerebrospinal fluid, the diagnosis was finally confirmed. Conclusion Disseminated Nocardiosis is an uncommon disease. This article will report a rare case of disseminated Nocardiosis simultaneously involving the lung, spinal cord, subcutaneous soft tissue and pituitary gland, especially with neuropathy as the initial symptom. Imaging is helpful for the early diagnosis of the disease and pathological and microbiological examinations are helpful for its confirming.

Attributes of intestinal microbiota composition and their correlation with clinical primary nonresponse to anti-TNF-α agents in inflammatory bowel disease patients

The largest microbial aggregation in the human body exists in the gastrointestinal tract. The microbiota in the host gastrointestinal tract comprises a diverse ecosystem, and the intestinal microbiota plays a vital role in maintaining gut homeostasis. This study aims to examine whether the gut microbiota influences unresponsiveness to anti-TNF-α treatments in primary nonresponder patients, and consequently identify the responsible microbes as biomarkers of unresponsiveness. Stool samples were collected from a cohort of patients with an established diagnosis of IBD, either ulcerative colitis (UC) or Crohn’s disease (CD), following completion of the induction phase of anti TNF therapy. 16S rRNA sequencing analysis was used to examine the pattern of microbiota communities in fecal samples. The quality and quantity of fecal microbiota were compared in responder and primary nonresponder IBD patients following anti-TNF-α therapy. As per our hypothesis, a difference in gut microbiome composition between the two patient subgroups was observed. A decreased abundance of short-chain fatty acid (SCFA)-producing bacteria, including Anaerostipes, Coprococcus, Lachnospira, Roseburia, and Ruminococcus, was detected in non-responsive patients, which was the hallmark of dysbiosis. Biomarkers of dysbiosis that were identified as predictors of clinical nonresponse, included Klebsiella, Eubacteriaceae, RF32, Bifidobacterium_animalis, and Muribaculaceae—previously known as S24-7. Signature biomarkers showed dramatic alteration in the composition of gut microbiota in patients who demonstrated primary nonresponse to anti-TNF-α agents. Dysbiosis, with features including a dropped biodiversity, augmentation in opportunistic pathogenic microbiota, and a lack of SCFA-producing bacteria, is a prominent feature of the microbiome of primary nonresponders to anti-TNF-α therapy.

Pharmaceutical Pollution: Azole Antifungal Drugs and Resistance of Opportunistic Pathogenic Yeasts in Wastewater and Environmental Water

The occurrence of residual antifungal agents through indiscriminate prophylactic use and inappropriate disposal has been reported in wastewater treatment plants (WWTPs), surface water, and groundwater environments. Opportunistic pathogenic aquatic yeasts develop resistance to commonly used antifungal agents through continued exposure to residual antifungal agents in environmental waters. This poses a major public health concern. The present review attempts to provide a brief description of antifungal drugs, with a focus on the most widely used class of antifungal drugs, the azoles, as emerging contaminants in environmental water. Routes of exposure of azole antifungal drugs in wastewater treatment plants, surface water, and groundwater are discussed. The presence of pathogenic yeasts in environmental water, the associated azole resistance, and the risk of exposure to humans and microbiota are highlighted. Management actions needed to curtail the spread and minimise the risks are also indicated. Further research on the occurrence of antifungal agents in wastewater and environmental water is vital to better understand and mitigate the associated health-related risks.

First Case of Subcutaneous Mycoses Caused by Dirkmeia churashimaensis and a Literature Review of Human Ustilaginales Infections

ObjectiveDirkmeia churashimaensis, belonging to Ustilaginales fungi, has never been reported as clinical pathogenic until very recently. In this study, we report an unusual subcutaneous infection with Dirkmeia churashimaensis and reviewed all human Ustilaginales infections. The aim is to better understand their epidemiology, infection type, risk factors, and the sensitivity to antifungal agents.MethodsAn 80-year-old female farmer developed extensive plaques and nodules on her left arm within 2 years. Pathological and microbiological examinations identified a new pathological agent, Dirkmeia churashimaensis, as the cause of this infection. The patient was successfully cured by oral itraconazole. We reviewed a total of 31 cases of Ustilaginales cases, among of which only three were skin infections.ResultsLocal barrier damage (i.e., surgery, trauma, and basic dermatosis) and systemic immunodeficiency (i.e., preterm and low birthweight, Crohn’s disease, malignant cancer, and chemotherapy) are risk factors for Ustilaginales infection. The D1/D2 and ITS regions are the frequently used loci for identifying the pathogens together with phenotype. Most patients could survive due to antifungal treatment, whereas seven patients died. Amphotericin B, posaconazole, itraconazole, and voriconazole showed good activity against these reported strains, whereas fluconazole, 5-flucytosine, and echinocandins usually showed low susceptibility. Itraconazole had good efficiency for subcutaneous infections.ConclusionsThe present case study and literature review reveal that Ustilaginales can be opportunistic pathogenic normally in immunocompromised and barrier damage people. A proper identification of fungi can be crucial for clinical treatment, and more data of antifungal are needed for choice of medication against this kind of infections.

Application of bacillus megaterium for subclinical mastitis in cows

The problem of treatment of subclinical mastitis often arises after calving, especially in cows of the first lactation. The paper presents the results of the therapeutic effect of Bacillus megaterium in subclinical mastitis in cows. The aim of the research. To determine the effect of Bacillus megaterium on the microflora of the gastrointestinal tract and colonies of microorganisms isolated from subclinical mastitis in cows. Materials and methods. The research was conducted in a dairy farm growing Holstein. Cows with subclinical mastitis of the experimental groups were given concentrated feed with the addition of Bacillus megaterium (1 × 109 CFU/g) at a dose of 15–35 g per animal. The control group of cows was given the usual diet for dairy cows. The experiment lasted 30 days. Results. The use of Bacillus megaterium (1 × 109 CFU/g) at a dose of 35 g per animal had a pronounced effect on the microflora of the gastrointestinal tract of cows. The amount of Lactobacillus sp. was 67 % higher and Bifidobacterium 58 % higher than the control. In addition, the level of opportunistic pathogens on Escherichia coli decreased by 45 %, Clostridium by 27 %, Enterobacteriaceae and Staphylococcus by 75 %, and Candida by 80 % compared to controls. The amount of microflora in milk decreased by 40.2 % and the number of somatic cells by 87.9 %. Conclusions. The therapeutic efficacy of Bacillus megaterium (1 × 109 CFU/g) at a dose of 35 g per animal for 30 days in subclinical mastitis has been proven. After treatment, the amount of microflora in cow's milk decreased by 40.2 % and the number of somatic cells by 87.9 %. A positive effect on the microflora of the gastrointestinal tract of cows, where the number of Lactobacillus sp. increased by 67 % and Bifidobacterium by 58 %. The level of opportunistic pathogenic microflora decreased by Escherichia coli – by 45 %, Clostridium – by 27 %, Enterobacteriaceae and Staphylococcus – by 75 %, Candida – by 80 %, compared to the control.

Post Covid-19 and Dentistry Revealing the silent condition - Rhino Maxillary Mucormycosis

The author would like to highlight the uncommon condition of rhinomaxillary mucormycosis which presents with a common complaint of periodontal abscess. This is highly significant in the current global scenario of the Covid-19 pandemic, as this deadly condition if diagnosed timely (by the dental surgeon) can save lives and prevent serious lifelong morbidity. Acute lung damage in Covid-19 was controlled worldwide by administering corticosteroids. This led to transient hyperglycemia, which coupled with low immunity served as an ideal environment for the fungal spore’s growth and proliferation.1 Species like Candida, Aspergillus and Rhizopus are normally not virulent in healthy individuals but can cause disseminated fatal infections in an immune-compromised host.2 Infection caused by these opportunistic pathogenic fungi present with non-specific symptoms and are often difficult to diagnose. Mucormycosis is the third most common opportunistic fungal infection caused by Rhizopus.3 Two such cases reported to the Department of Periodontics, Maulana Azad Institute of Dental Sciences, New Delhi with similar oral findings and common history of Covid-19 recovery. Both the patients were on 3 weeks of steroid therapy during which they had transient hyperglycemia. After 4 weeks of recovery, they developed painful gum boil/s. Clinical findings revealed periodontal abscess and tooth mobility.